The present invention relates in general to sewing machines and in particular to a new and useful edge guiding device for guiding edges of a workpiece having a plurality of edges extending at angles to each other on which parallel seams are to be sewn.
U.S. Pat. No. 2,977,908 discloses an edge guiding device wherein, when sewing the corners of collars or cuffs, the device is moved by an actuator from its active position into an inactive position transversely to the work feed direction. This is to allow the collar or cuff to be turned into the correct position, for the next following seam section, unhindered by the guiding edge device.
For certain seams, for example the seams between the collarband and the corner of the collar, the first of which is sewn from the collarband toward the corner and the seam opposite to it is sewn from the corner toward the collarband progressively, this known edge guiding device cannot be employed from the start of the sewing operation. This is because the protruding parts of the collarband provided for the buttonhole and for the button permit the edge guiding device to be brought to the collar edge only after the sewing of a certain seam distance. The guiding of the collar is therefore not possible at first during the sewing of the first seam. Later the collar can be guided only at the relatively short vertical guide face. For the seam to be formed along the long, usually curved collar edge between the guiding face and collar would be advantageous. When sewing the second seam advancing from the collar corner to the collarband, the edge guiding device must be taken out of its active position even before termination of the seam, so that the collar will be moving without positive guiding at an early stage.
A seamstress can attenuate these weak points during guiding of the workpiece by doing her own guiding. In automated systems, however, where the work is simply placed in readiness in proper orientation while the rest of the manipulation, including the seam formation, takes place automatically, the work must be guided continuously and be held under control exactly. Assistance by the operator is not possible here.